What is the function of mitochondria in eukaryotes

What did hunter gathers do to alter the environment?

Veins have a much lower blood pressure than arteries. which of these prevents backflow of blood in veins? a. pressure applied by the heart b. one–way valves in veins c. thin muscular walls of veins

Compare the shapes of the bones of the human skull with the shapes of the bones of the human leg. how do the shapes differ? why are the shapes important?